1. Field of the Invention
The present invention relates to a fluid supply valve attachment device that attaches a fluid supply valve to a fixing member in a stationary manner.
2. Description of the Related Art
A fluid supply valve attachment device that attaches a fluid supply valve to a fixing member in a stationary manner is conventionally known (Japanese Patent Application Publication No. 2005-23975 (JP-A-2005-23975)). The fixing member that attaches the fluid supply valve in a stationary manner has: a first passage through which fluid passes; a recessed fitting section; an internal thread formed in the inner periphery of the recessed fitting section; a reference inner peripheral surface in the shape of a cylinder; and a ring-shaped stopper surface that is radially extended. The fluid supply valve has: a second passage that can communicate with the first passage; a valve body capable of opening/closing the second passage; and a protruded insertion section that is inserted in and attached to the recessed fitting section of the fixing member. The protruded insertion section has a cylindrically-shaped reference outer peripheral surface that is fitted to and restrained by the reference inner peripheral surface of the recessed fitting section.
According to the above device, in order to attach the fluid supply valve to the fixing member, an external thread is threaded into the internal thread while the reference outer peripheral surface of the protruded insertion section is fitted to and restrained by the reference inner peripheral surface of the recessed fitting section. Accordingly, the protruded insertion section of the fluid supply valve is radially positioned and then fitted to the recessed fitting section of the fixing member. In this case, “scoring” may occur between the reference outer peripheral surface of the protruded insertion section and the reference inner peripheral surface of the recessed fitting section.
In addition, in a field that requires air tightness, the above-mentioned “scoring” tends to occur when clearance between the reference outer peripheral surface of the protruded insertion section and the reference inner peripheral surface of the recessed fitting section and clearance between the internal thread and the external thread are designed to be as small as possible.
For the above reason, according to the above-mentioned JP-A-2005-23975, the protruded insertion section is divided into two parts: one is a first part with the reference outer peripheral surface, and the other is a second part with the external thread. The first and second parts are adopted to be radially and independently displaceable. However, the division of the protruded insertion section into the two parts increases the number of parts, thereby complicating the manufacturing process.